Hydraulic power transmitting mechanism



NOV. 14, 1933. JU4NKEURS 1,935,400

HYDRAULIC POWER TRANSMITTING MECHANISM Filed May 28, 1929 4'Sheets-Sheet2.

. Inventor: Hayofuhfiers y C Nov. 14, 1933. H. JUNKERS 1,935,400

HYDRAULIC POWER TRANSMITTING MECHANISM Filed May 28, 1929 4 sheets-sheets Inventor: hayo .7Zm/iens Nov. 14, 1933. H. JUNKERS 1,935,

HYDRAULIC POWER TRANSMITTING MECHANISM Filed May 28. 1929 '4Shqgts-Sheet 4 /n Vehivr:

Hu da fun/fer:

Patented Nov. 14 1933 HYDRAULIC-POWER TRANSMITTING rmcnms u HugoJunkers, Dessau, Germany Application May as, 1929, Serial No. 366,63 andGermany May 29, 1928 7 Claims. (01. 1912- -61) My invention relates tohydraulic power-transnutting mechanisms and more particularly tomechanisms in which power is transmitted by the static pressure of .aliquid. Such mechanisms 5 comprise members which, when the mechanism isslipping, act in the manner of a pump, delivering liquid through a pipeincluding regulating means while a corresponding quantity of liquid isdrawn into the mechanism through a' suction pipe. It is desirable that"the cross-sectionalarea of the suction and delivery pipes should besmall in order to reduce the cost, size and weight of the mechanism, butthis involves the drawback that the .resistance'to flow in the pipebecomes so high even with the regulating means full open that it is notpossible to reduce the velocity of the driven part to the desired extentor to arrest this part.

It is an object of my invention to overcome this drawback and to providea wider regulating range. To this end I provide regulating orrestricting means not only in ,the delivery, but also in the suctionpipe line. By these means it is possible to reduce the quantity ofliquid admitted to the systemto such an extent that its discharge at thedelivery end is not interi'erred with by the small area or restrictionof the delivery pipe.

By regulating the area of the suction pipe the quantity of liquidflowing in the members per unit of time may be reduced as desired; The

smaller the quantity, the smaller the pressure for conveying the liquidthrough the members and the larger .the' slip, as the torque transmittedis in proportion to the pressure. The suction pipe may be throttled orrestricted to such an extent as to generate a considerable vacuum on thesuction side of the members, or air or a mixture of air and liquid maybe introduced in the last stages instead of liquid, and this permitsregulation of the slip within very wide limits notwithstanding a smallcross-sectional area of the pipe lines. In the drawings afiixed. to thisspecification and forming part thereof a hydraulic mechanism embodyingmy invention and various means for regulating it are illustrateddiagrammatically by way of example.

- In the drawings Fig. 1 is a diagrammatic and partly sectionalelevation of a mechanism, and

Fig. 2 is a section on the line 11-11 in Fig. 1,-

drawn to a larger scale,

- Figs. 3, 4, and 5 are sectionsof various regulating means,

to Fig. 3 fitted'to rotate .with the driven shaft 'gear case on thedriving shaft,- 4 and 5 are Figs. 6, '7, and 3 are sections on the lineVI-VI in Fig. 5 showing various positions of the regu-" lating meansillustrated in Fig. 5.

liquid supply tank, 21 is a cooler connected with the supply tank, 22 ispart of the suction pipe,

A is a regulating valve at the end of the pipe 22, 23 is an extension ofthe suction pipe beyond the valveA, 24 is a branch pipe extending fromthe suction pipe 23 .to a sleeve 11 on the driving shaft 1, 10 is a borein the driving shaft extending from the sleeve 11 to a suction chamber 7in the casing 6 which, as shown in Fig. 2, has two diametrally oppositeopenings near the points of mesh of the planet gears 4 and 5 with thesun gear 3, and a duct connecting such openings with the suction bore10., 8, 8 are the openings of a delivery chamber which are arrangedopposite to i the openings 7, '7 of the suction chamber and areconnected with a delivery bore 12 in the driving 8 shaft 1. 13 is asleeve surrounding the end of the bore 12, 31 is adelivery pipeconnected withv the sleeve 13, C is a regulating valve at the end of thepipe 31, and 32 is an extension from the valve C to the supply tank 20.

25 is a pipe connected to the suction pipe 23 at the rearo'f the valveA, B is a regulating valve at the end of the pipe, 26 is a dischargepipe beyond the valve B which is preferably taken to the supply tank 20,27 is a pipe also connected to the suction pipe 23, 28 is a safety andcheck valve at the end of the pipe loaded by a light spring, and 40 is asump to which the valve 28 delivers. 52 is the casing of a check valveconnected to the suction pipe 22 in front of the valve A, 53 is a pipeextending from the check valve casing to above the sump 40, 31' is apipe connecting it with the delivery pipe 31,..and 54 is a safety andcheck valve at the end of the pipe which is loaded by a somewhatvheavier spring 105 than that of the valve 28.

41, 43 is a by-pass connecting the pipes 22 and 23 past the valve A, 42is a pump in the by-pass,

'44 is a restriction in the delivery pipe 43of the pump, and 46 is alubricating nozzle branched It will appear that the pump 42 is able tosup-, ply a small quantity of liquid to the casing 6 when ,5 the valve Ais closed while the valves B and C are open. llf these valves are closedso that flow through ,the casing 6 is prevented the liquid delivered bythe pump is discharged through the valve 28 or through the nozzle 46.Any number of lubricating stations supplied by the pump 42 may obviouslybe provided. The lubricant'from the stations flows to the sump 40. 49 isa pump drawingfrom the sump and delivering the liquid to the supply tank20 through the pipe 32 to which its delivery pipe is connected, ordirected. I Q

When it is desired to operate the mechanism without slip the valve A inthe suction line 22, 23 is opened and the valves B and C are'closed.Should excessive pressure build up in the system, the safety valve 54opens to discharge into the ,sump 40. When it isdesired toreduce thevelocity of the driven shaft 2 the. valve'C in the delivery line 31, 32is opened so that the pressure) in the system is reduced. The casing 6now acts as a pump, drawing liquid from the supply tank 20, past valveA, sleeve 11, bore 10 and the openings '7, 7 and returning it to thetank 20 through the openings 8, 8, bore 12, sleeve 13, and pipe line 31,32. If, with the valve C full open, the velocity of the driven shaft 2is still too high,.the' valve Ais gradually closed so as to reduce thequantity of liquid drawn into the casing 6 per unit of time. When thevalve A is completely closed a considerable vacuum is generated in thesuction line 22, 23, 10, which is often undesirable. It is removed bymeans of the valve B which upon being opened permits air to be drawninto the casing 6 through the pipes 26, 25, sleeve 11, and bore 10. Asit is possible to convey air through the system at very low pressure theslip is considerablyincreased by this expedient. The gears in thecasing'6 will not run dry as the pump 42 always supplies a small quantity ofliquid to the sleeve 11. The pump 42 might, however, be dispensed withand some leakage might be provided at the valve A but'in this case thequantity of liquid admitted can not be" regulated exactly as its flow isinfluenced by the variations of viscosity. with temperature. On theother hand, the quantity of liquid delivered by the pump 42 ispractically constant, I

If, with lthe valve B open, the driven shaft 2 leads so that'the casing6 delivers liquid in reversed direction thisliquid returns to the tank20 through pipes 25, 26. If the valves A and B are closed with thedriven shaft leading the reverse flow of liquid is discharged to thesump 40 past the valve 28 in pipe 27. In order to prevent excessivevacuum and in order to supply the member 6 with lubricant, the pipe 53with the check valve 52 is provided, which, however, preferably allowsonly a small quantity of liquid to pass and thus promotes slip in thesame manner as the valve A does when throttled down considerably undernormal operating conditions.

Combining the liquid supply to the casing 6 with a lubricating system,pump 42 and nozzle 46 involves the advantage. that even when the gear isshut down for a longer period still there is circulation of oil heatedby the mechanical energy transmitted through the cooler 21 so that whenthe cooler is only a radiator, that is, is

cooled only by contact with the ambient air, the

liquid will remain thin enough even at very low ambient temperatures. Inorder to simplify the arrangement and the regulation of the mechanismthe three valves A. B, 'C may" be combined into a single'unit,preferably a balanced piston valve, and examples of such combinationvalves will now be described with reference to. Figs. 3 and.4 in whichis a valve casing in which the piston valve 61 is fitted to slideaxially. The pipes 23 and 31 are connected to a single sleeve 110 whichreplaces the sleeves 11 and 13 in Fig. 1.

( Referring first to Fig. 3, the piston valve 61 in the casing 60'isadapted to be displaced axially therein through the medium of a rod 63,which may be actuated by any suitable means, not

shown. The piston valve controls three rows of slots which correspond tothe valves A,B, and C and the pipes opening into the casing 60 aredesignated by the same reference numerals as in Fig. 1. The pipe 25 isreplaced by an inclined bore"25' in the piston valve 61. The slots A andC are controlled by the upper and lower ends of the valve, and the slotsB are controlled by a central groove 62 in the valve. Assume the pistonvalve to be at the lower end of its stroke, the slots A are open and theslots B and C are closed. The mechanism operates without slip. Whenthepiston is raised the slots C are opened gradually. so that the mechanismoperates as a pump and the slip increases. In the position illustratedthe slots A are still open, and"the slots C are full open. When thepiston is raised further the slots A are gradually throttled and themechanism now still operates with slip but under a vacuum on the suctionside until the upper edge of the gr ove 62 opens the slots B, admittingair from pipe 6 through the bore 25' to the pipe 23 at the rear of theslots A. 0

Referring now to Fig. 4 the piston. valve 61'' is divided into twovalves 61 and 64, the valve 61' controlling the slots A and B asdescribed, and the valve 64 controlling the slots C. 68 is a rodextending from the upper piston valve 61' into'a cavity at the top ofthe lower valve 64, 67 is a flange at the lower end of the rod, and 66is a spring inserted between/the two valves. 65 is an extensionat thelower end of the valve '64 which controls the by-pass 43-from' the pump42, Fig. 1. 70 is' a row of slots connected with 43 and controlled by"the lower endof the extension 65, 69 is a chamber into which the slots70 open, 71 is a spring-loaded check valve connecting the pipe 43 withthe chamber 69, 72 is a narrow passage extending from the chamber 69 toa pipe 43' connected with the pipe 23, and 75 is by the valve'6l and theoperation is the same as described with reference to Fig. 3. When,however, the piston valve 61' is lowered, it is connected with the lowervalve 64 only by the spring 66. When the extension 65 closes the slots'70 the slots C have only been partly closed by the valve 64. When theslots '70 have been closed the liquid in the chamber 69 can escape onlythrough the narrow passage '72 so. that the lower valve 64 follows theuppervalve 61' only slowly even if the upper valve is lowered rapidly,and the slots C are closed gradually. In this manner the mechanism isthrown in gradually and without jerks and the liquid which has beenheated while and undesired slip to'a minimum. The ports '70 closed sothat the system is in full gear. When the body 81 is rotated into theposition Fig. '7 the may be supplied from the pump 42 through bypasspipe 43. The liquid from the chamber 69 is discharged through the pipes43' and 23.

Preferably the casing is heated so that the piston valves will'move'sweetly. The heating passages '75 are provided with this object,be-

ing supplied with heated liquid, in the present instance the liquidwhich the pump 49 delivers through the pipe 50 which liquid stillcarries the heat of the lubricated parts. The heating liquid isdischarged into pipe 32 through pipe 50'.

Referring now to Figs. 5 to 8, these show a rotary regulating unit whichis arranged on the driving shaft 1 instead of the sleeves 11 and 13,Fig. 1. A rotary valve body 81 is inserted between a stationary sleeveand the driving shaft 1 and is provided with .a handle 82, or it may beprovided with means, not shown, connecting.

it with regulating means of any type. 83 and 84 are grooves on theinside of the valve body 81 which extend all over its perimeter, thegroove 83 cooperating /with the suction bore'10 and the groove 84cooperating with the delivery bore 12. From each groove a passage 85 and86, respectively, extends vto the outside of the body81.

is a pin on the body 81 which prevents axial displacementof the body 81with respect to the sleeve 80 and also limits the rotation of the bodywith respect to the sleeve by engaging a groove 94 therein. The openingsin the sleeve 80 corresponding to the three regulating valves areindicated at A, B, and C, where the pipes 22, 26,

and 32\are connected with the sleeve 80. On the suction side, a passage91 is "provided to which are connected the combined pipes. 27 and 43,and on the delivery side a passage 92 is provided to which are connectedthe combined pipes 53 and 55. In theposition illustratedjq iriFig. 6 thepipe 22 corresponding to valve A is connected with the suction bore 10through groove 83 and passage 85 and the pipe 32 corresponding to valveC is opening C remains open but the opening A'- is increasinglythrottled and finally closed, Fig. 8.

Shortly before the position Fig.8 is attained the opening B of pipe 26is laid open by the passage 85 so that air is admitted to the mechanismwhich is now operating at maximum slip. The openings -91 and 92 of pipes27, 43 and 53, 55 are so arranged thatin all positions of the body 81the opening 91 is connected with the suction bore 10, and the opening 92with the delivery borev 12.

This valve has the advantages of great simplicity as it is without anypipes between it and the mechanism which require placing outside theparts of the mechanism, and "of reliability, as the body 81" is notrotating with the system and therefore is readily handled and inspected.

Referring now to Fig. 9 the regulating unit which is designed like theunit illustrated in Fig. 3., with its piston valve 61, and the supply,tank 20 are combined torotate with the casing 6. The tank'is eifectivelycooled on account of intense radiation by its rapid rotation,- ribs 21'being preferably provided for increasing its' surface. 98 is a fillinghole in the tank which is equipped with an extension 99 of such lengththat the tank cannot be completely filled with liquid but will alwayscontain some air, and

when the casing 6 rotates the liquid forms an annulus surrounding an airspace into which open to be limited to the exact details of constructionshown and described for obvious modifications will occur to a personskilled in the art. v In the claims afllxed to this specification noselection of any part'cular modification of the invention is intended tothe exclusion of other modifications thereof and the right tosubsequently make claim to any modification not covered by theseclaimsis expressly reserved, r

I claim:

1'. A hydraulic power-transmitting mechanism comprising adriving and adriven part, a suction pipe for supplying liquid to, and a delivery pipefor discharging liquid from, said parts,,and means for gradually openingsaid delivery pipe and thereafter gradually closing said suction pipe.

2. A hydraulic power-transmitting mechanism comprising a driving and adriven part, a suction pipe for supplying. liquid to, and a deliverypipe for discharging liquid from, said parts, means for graduallyopening said delivery pipe and thereupon gradually closing said suctionpipe, an air .inlet connected to said suction pipe intermediate saidclosing means and said parts, and means for opening said air inlet aftersaid suction pipe has been closed.

/3. A hydraulic power'transmitting mechanism comprising a driving and adriven part, a casing connected to said parts and having openings, adelivery pipe, a suction pipe and an air inlet pipe connected to saidopenings, and a slide adapted -to move in said casing and to controlsaid openings in succession.

4. A hydraulic power-transmitting mechanism comprising .a driving and adriven part, a suction pipe for supplying liquid to, and a delivery pipefor discharging liquid from, said parts, means for gradually openingsaid delivery pipe and thereupongradually closing said suction pipe, apipe by-passing said closing means in said suction pipe, andfmeans forsupplying liquid to the pipe beyond said closing means when saidclosingmeans areclosed.

5. A hydraulic power-transmitting mechanism comprising a driving and adriven part, a suction pipe for supplying liquid to, and a delivery pipefor discharging liquid from, said parts, means for gradually openingsaid delivery pipe and thereupon gradually closing said suction pipe, apipe by-passing said closing means in said suction pipe, means forsupplying liquid to the pipe beyond said closing means when said closing'nected to said liquid-supplying means for supplying liquid from saidby-passing pipe to continuously operatingjparts of said mechanism.

6. A hydraulic power-transmitting mechanism,

comprising a driving and a driven part, a suction pipe for supplyingliquid to, and a delivery pipe for discharging liquid from, said parts,means for gradually opening said delivery pipe and thereupon graduallyclosing said suction pipe,

and means for conducting said liquid to permanently rotating parts ofsaid mechanism.

7. A hydraulic power transmitting mechanism comprising a driving and adriven part, a suction 5 pipe for supplying liquid to, and a deliverypipe 0 for discharging liquid from, said parts, means for

